1. Field of the Invention
The present invention relates to a communication control apparatus and a communication control method.
2. Description of the Related Art
At the present, there exist a variety of communication networks such as a mobile network, Hot spot (registered trademark) and the Internet. Then, in these communication networks, respective technologies support keeping a communication quality (quality of service: QoS), ensuring the security against interception and switching over a communication route without any interruption of the communications.
Generally, an advanced error correcting code is applied to keeping the quality of service (QoS). The advanced error correcting code is a coding method in a way of adding a redundant piece of information to digital data. Then, the advanced error correcting code is a method of correcting, if an error occurs in part of the coded digital data due to a noise etc. during a transfer of the digital data, this error with the redundant information added to the digital data. A case of applying the advanced error correcting code to packet communications across the Internet is stated. In the case, a packet size increases depending on the redundant information added to the data. Further, when the packet size increases, a congestion gets easy to occur on the communication control apparatus in the communication network. Then, when the congestion occurs on the communication control apparatus in the communication network, the packets equal to or more than an error-correctable quantity of the packets might be discarded. Hence, avoidance of this congestion needs having a width in time, when sending the packets, thereby avoiding the congestion. From this point of view, the advanced error correcting code has a defect that the packet size becomes large and a defect that a processing delay gets large because of adjusting the time width for sending the packets.
As for ensuring the security against the interception, IPsec (IP security protocol) is a general protocol. This method is a technology scheming to make an interceptor unable to decrypt a content of the communication information by encrypting the information with an algorithm such as DES (Data Encryption Standard) and AES (Advanced Encryption Standard).
On the other hand, a general technology for switching over the communication route without any interruption of the communications is a multihoming technology for ensuring a communication route to which the communication route is switched over while ensuring the in-use communication route, and switching over the communication route by taking synchronization between a transmitting terminal and a receiving terminal. SCTP (Stream Control Transmission Protocol) is given as a transport layer protocol that supports the connection between the plurality of routes that employs the multihoming technology. In addition to the switching method of switching over the communication route by taking the synchronization, there exists a method of transmitting the same packet to both of a new communication route and an old communication route by multicasting.
As described above, the technologies respectively support keeping the QoS, ensuring the security against the interception and switching over the communication route without the interruption of the communications. Hence, a defect is that the processing time for sequentially executing these technologies is needed.
Further, a variety of adjusting parameters are required for implementing these technologies, and therefore the communication control apparatus is required to hold a great number of these adjusting parameters.
The following are related arts to the present invention.    [Patent document 1] Japanese Patent Application Laid-Open Publication No. 2004-274703    [Patent document 2] Japanese Patent Application Laid-Open Publication No. 2005-57487    [Patent document 3] Japanese Unexamined Patent Publication No. 2004-529533